T-test in R

a=c(12.9, 13.5, 12.8, 15.6, 17.2, 19.2, 12.6, 15.3, 14.4, 11.3) 
b=c(12.7, 13.6, 12.0, 15.2, 16.8, 20.0, 12.0, 15.9, 16.0, 11.1) 
t.test(a,b)

## 
##  Welch Two Sample t-test
## 
## data:  a and b
## t = -0.043323, df = 17.653, p-value = 0.9659
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -2.478112  2.378112
## sample estimates:
## mean of x mean of y 
##     14.48     14.53

t.test(a,b, paired=TRUE)

## 
##  Paired t-test
## 
## data:  a and b
## t = -0.21331, df = 9, p-value = 0.8358
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -0.5802549  0.4802549
## sample estimates:
## mean of the differences 
##                   -0.05